Relationships between winter wheat yields and soil carbon under various tillage systems

Transcription

1 Reltionships etween winter whet yields nd soil cron under vrious tillge systems O. Miknová, T. Šimon, M. Jvůrek, M. Vch Crop Reserch Institute, Prgue-Ruzyně, Czech Repulic ABSTRACT Soil qulity nd fertility re ssocited with its productivity, nd this in turn is connected to the soil iologicl ctivity. To study these effects, well designed long-term field experiments tht provide comprehensive dt sets re the most pplicle. Four tretments (tillge methods) were set up: (1) conventionl tillge (CT); (2) no tillge (NT); (3) minimum tillge + strw (MTS), nd (4) no tillge + mulch (NTM). Our ojective ws to ssess the reltionships etween soil microil chrcteristics nd winter whet yields under these different techniques of conservtion tillge within field experiment, originlly estlished in The differences in verge grin yields over time period etween the vrints were not sttisticlly significnt. Orgnic cron in the topsoil ws higher in plots with conservtion tillge (NT, MTS, nd NTM), thn in the conventionl tillge plots. There ws sttisticlly significnt correltion (P.1) etween the grin yields nd orgnic C content in topsoil. Keywords: soil tillge; Triticum estivum; soil orgnic C; microil iomss C Soil qulity, which determines the soil fertility nd productivity of groecosystems, is n importnt ojective of sustinle griculture (Melero et l. 26, Roger-Estrde et l. 21). Arle lnds under cultivtion differ drmticlly from ntive soils. The periodic utiliztion of conventionl tillge prctices ffects the top soil lyer, nd my led to oth decline of the soil s orgnic mtter s well s to soil erosion. In ddition, excessive tillge cn produce compction, soil crusting, nd dmge to the soil iot (Kldivko 21). To mitigte these prolems, conservtion soil tillge technologies (no-till nd reduced tillge) hve een dopted worldwide. Nevertheless, prcticl experience hs shown tht they re not universlly pplicle (Friedrich 23). In Europe, conservtion griculture ws less widely dopted thn in other regions of the world, nd the reduced tillge is more often used thn the no tillge (Lhmr et l. 26). Vn den Putte et l. (21) reviewed nd ssessed the effects of soil tillge on crop yields, using 47 studies from 75 sites ll over Europe. Their nlysis showed tht the introduction of conservtion tillge in Europe my hve some negtive effect (c. 4.5%) on yields. However, no significnt crop yield reduction ws oserved with deep reduced tillge (RT). On verge, for deep RT, the yields re even somewht higher thn for the conventionl tillge; except with mize. Sustinle soil mngement systems not only require the proper choice of cropping methods, tillge techniques, s well s ensuring supply of nutrients; ut they lso require susequent soil qulity evlutions. It is well known tht soil qulity nd fertility re connected to the iologicl ctivity of soil. The iochemicl properties of soil re widely used to evlute soil qulity. Among the generl prmeters, the microil iomss C is considered to e the most relile. In the Czech Repulic, conventionl tillge is the predominnt method of lnd preprtion. Nevertheless, out 18% of the griculturlly used lnd y 25 ws converted to reduced tillge, nd out nother 3.5% to no tillge (Lhmr et l. 26). Pst reserch on conservtion griculture focused on oth the effects of the tillge prctices on the crop yields (Šíp et l. 29) nd the soil qulity (Miknová et l. 29). To study such effects, well designed long-term field experiments tht cn provide comprehensive dt sets re the most Supported y the Ministry of Agriculture of the Czech Repulic, Project No. MZE PLANT SOIL ENVIRON., 58, 212 (12):

2 suitle. Bsed on these, oth short nd long-term chnges in soil nd crop trits cn e evluted, nd specific trends chrcterizing conversion nd the sttionry phse of conservtion tillge cn e defined. Our ojective ws to ssess the reltionships etween soil microil chrcteristics nd winter whet yields under different techniques of conservtion tillge nd crop mngement in field experiment, originlly estlished on n orthic Luvisol in MATERIAL AND METHODS Field experimentl design. Since 1995, the experiment hs een continuously conducted in n re with temperte semirid climte, 338 m.s.l., nnul men ir temperture of 8.2 C, nd n nnul men precipittion of 477 mm. The field experiment ws estlished s rottion of three crops: winter whet (Triticum estivum L.), spring rley (Hordeum vulgre L.), nd pe (Pisum stivum L.). A split plot method, with four replictions, ws used. Four different tretments (tillge methods) were set up: (1) conventionl tillge (CT), i.e. mouldord ploughing to depth of.2 m, usul seed ed preprtion nd sowing; (2) no tillge (NT), i.e. sowing with specil drill mchine into non-tilled soil; (3) minimum tillge (MTS), i.e. shllow tillge (out 1 cm deep) nd chopped strw with the post-hrvest residues of the ctchcrop incorported; (4) no tillge + mulch (NTM), i.e. direct drilling into non-tilled soil, covered with the ctchcrop post hrvest residues nd chopped strw. The field site hs soil of cly-lom texture (Orthic Luvisol, FAO Txonomy), with ulk density within the rnge from 1.57 (CT) to 1.65 g/cm 3 (NT) in the upper lyer (.1 m) of the topsoil, ph KCl 7.7, electricl conductivity 12.5 ms/m, totl N.164%. All crop stnds (including CT) were sown with John Deere 75A drill mchine. Minerl nitrogen fertiliztion ws used for ll crops (i.e. 1 kg N per h for winter whet). In the MTS tretment, the strw from the cerels were incorported into the soil with nitrogen (mmonium form) t dosge of 1 kg per 1 kg of strw. In the MTS nd NTM tretments, 3 kg nitrogen fertiliztion ws used for ctchcrop. The ctchcrop ws hrvested nd post hrvest residues were incorported into the soil. The P nd K fertilizer doses were determined nd pplied ccording to the P, K content in the soil. Stndrd hericides were used, depending on the intensity of weed infesttions. Grin yields were determined on 24 m 2 test re, t the time of hrvest. Soil smpling nd smple processing. Soil smpling from ws crried out nnully t the eginning of Octoer from the CT, NT, MTS, nd NTM tretments from the topsoil, t depths of.1 m, t three sites from ech individul plot. The moist field soil smples from ech plot were mixed together (1 kg totl per plot), sieved to 2 mm, nd then stored in refrigertor t 4 C. Microil iomss cron (C-iomss) ws determined y the fumigtion extrction method (Vnce et l. 1987). Totl orgnic C (C org ) ws determined on VARIO MAX nlyser (Elementr Anlysensysteme GmH, Hnu, Germny) on ir-dried soil smples. Averges nd correltions etween the individul chrcteristics were clculted using Microsoft Excel nd Sttistic CZ softwre. Tukey HSD tests were used for determining significnt men differences. Columns which re designed y the sme letter did not differ significntly (P =.5). The correltion mtrix of different properties ws sed on Person correltion coefficients (P <.1 nd P <.5). The reltionships were tested y mens of liner regression. RESULTS AND DISCUSSION Averge vlues of winter whet grin yields in the selected tillge tretments during the period from 22 to 29 re shown in Figure 1. The whet yields re presented from 22 ecuse we strted our investigtions of the iologicl soil properties in tht yer. There were rther high fluctutions in the grin yields until 26, due to dpttions of the soil properties to the conservtion tillge, nd wether conditions in individul yers. Grin yields pprently hd stilized y 26, which is eleven yers fter the eginning of the experiment; therefter, they stedily grew in vrints under conservtion tillge. As shown in Figure 1, the differences in grin yields mong the tretments did not differ significntly. These differences were minly dependent on the wether conditions in the given yers. The men grin yields rnged from 3.9 t/h to 8.45 t/h until 26. Severl uthors point to lrge vritions of grin yields during the first yers fter setting up soil conservtion technologies, s result of oth the dpttion to the soil properties nd vritions of the wether conditions. Significnt effects of the yer on the yield re widely documented in long- PLANT SOIL ENVIRON., 58, 212 (12):

3 Yield (t/h) Figure 1. Averge vlues of winter whet grin yields in four tillge tretments. CT conventionl tillge; NT no tillge; MTS minimum tillge + strw; NTM no tillge + mulch over the time period from 22 to 29 term field studies (Šíp et l. 29, Videnovič et l. 211). Lhmr (21) summrized the results of the KASSA project, which showed tht within Europe conservtion griculture does not necessrily generte increses in yields. In northern Europe, on verge, yields on poor nd medium fertile soils did not chnge drmticlly (±1%); on very fertile soils they slightly decrese with highly intensive level of production. It is lwys importnt to keep in mind the introduction of soil conservtion technologies, tht the fvorle effects re exhiited lter, fter the stiliztion of the soil properties. The length of this period depends on severl fctors, primrily on soil fertility, s well s on the locl soil nd climte conditions. Figure 2 shows the sum of precipittion nd the verge tempertures during the growing sesons (IV IX) during the period The first distinct difference in grin yields etween the conventionl tillge nd conservtion tillge ws found in 23. All vrints of reduced tillge performed etter thn the conventionl one did. The wether in 23 ws chrcterized y drought (264.2 mm; the long-term men eing 356 mm) nd high tempertures during the vegettion period (16.7 C; the long-term men eing 15.7 C). Another exmple of the eneficil effects of conservtion tillge on the yields of winter whet grin ws seen in 27. The very low grin yield in the conventionl tretment (CT 5.9 t/h), compred to soil conservtion technologies (NT 7.8 t/h, MTS 8.2 t/h, nd NTM 8. t/h) ws due to the very low precipittion in Mrch (14.5 mm; the long-term men eing 36. mm) nd April (2.4 mm; the longterm men eing 34.5 mm). Other oserved yers did not differ from the long-term verge (nnul men ir temperture of 8.2 C, nd n nnul men precipittion of 477 mm). The dvntge of soil conservtion technologies in dry yers were lso mentioned y Jos nd Hereter (25), who found higher mount of precipittion ccumulted in the soil under no-tillge, thn under conventionl tillge. The mount of the wter in the top.2 m of the soil decresed significntly from system to system in the following sequence: NT > MT > CT. However, this incresed quntity of wter did not deliver ny incresed crop production. Also Moreno et l. (1997) reported tht the yields of the whet crop, nd lso of sunflower, were slightly higher in the conservtion tillge tretment thn in the trditionl tillge. They concluded tht the conservtion tillge seems to e highly effective in enhncing oth soil wter rechrge nd wter conservtion, prticulrly in those yers with precipittion tht is much lower thn verge. These results indicte tht the min driving force in the spred of soil conservtion technologies is the etter utiliztion of soil wter, nd reduction of non-productive evportion due to mulching of the soil surfce with crop residues. Figure 1 lso shows tht from 26 (which is 11 yers fter the experiment ws estlished) there ws continuous growth of the grin yields on the soil conservtion tretments; except for NTM in 29. Grin yields were greter thn 8 t/h (even reching 1 t/h in the NT tretment while it fluctuted etween 6 8 t/h in the CT tretment. The men grin yields rnged from 5.9 t/h to 1. t/h from 26. In ccordnce with our results, Arrúe et l. (27) documented tht the yields of crops were generlly 1 15% higher under no tillge, in most studies tht were crried out in Spin, especilly in dry yers. So et l. (29) lso found yield stiliztion 5 yers fter the estlishment of their experiment. They showed tht over the first 5 yers the (mm) precipittion verge temperture ( C) Figure 2. Sum of precipittion, nd verge tempertures during growing seson (IV IX) throughout PLANT SOIL ENVIRON., 58, 212 (12):

4 C org (%) Figure 3. Averge vlues of orgnic C content in topsoil under different tillge systems over the time period from 22 to 29. CT conventionl tillge; NT no tillge; MTS minimum tillge + strw; NTM no tillge + mulch. Columns which re designed y the sme letter did not differ significntly (P =.5) Yield (t/h) 1 CT 8 NT MTS NTM 6 CT NT MTS NTM C org (%) Figure 4. Reltionship etween winter whet yields nd vlues of orgnic C content in topsoil under different tillge systems during the period 22 to 29. CT conventionl tillge; NT no tillge; MTS minimum tillge + strw; NTM no tillge + mulch nnul soyen yields of the NT tretments were consistently less thn, or equl to, those resulting from CT. However, CT ws unle to sustin the greter yields; nd from 5 yers, onwrds, the yields of the NT tretments were typiclly greter thn those of the CT. Orgnic cron content (C org ) in the topsoil in individul tretments is presented in Figure 3. Orgnic cron in the topsoil ws higher in the plots with conservtion tillge (NT, MTS, nd NTM), thn in the conventionl tillge (CT) plots over the entire time period. A sttisticlly significnt nd higher C org content ws found in the NT nd the MTS systems, when compred to the CT. Reltionships etween winter whet yield nd orgnic C content re presented in Figure 4. Liner regression lines show positive reltionships etween the orgnic C content in soil nd winter whet grin yields in ll tretments. These close reltionships re supported y correltion coefficients etween the two dtsets shown in Tle 1. There ws significnt correltion (t the.1 level) etween the yields nd C org contents in the topsoil. Tle 1. Person correltion mtrices mong the winter whet grin yields, orgnic C content nd microil iomss in topsoil during the period 22 to 29 Yield C org C org.571** C iomss **indicte significnt correltion t the.1 level of significnce Microil iomss content (C iomss ) in the topsoil in individul tretments is presented in Figure 5. Averge vlues of microil iomss C content in topsoil were gin higher in plots with conservtion tillge (NT, MTS, nd NTM) thn in the conventionl tillge (CT) plots. A sttisticlly higher iomss C content ws found in the MTS nd NTM tretments. A higher vriility of iomss C vlues proly cused lower vlues of correltion coefficients etween C iomss nd C org contents, s well s etween C iomss nd grin yields. They re not sttisticlly significnt (Tle 1). Microil C dynmics re more dependent on the fluctutions of the orgnic mtter input, temperture, nd moisture during the vegettion period; time while the crop yields nd totl orgnic C content in the soil re more C-iomss (µg C/g) Figure 5. Averge vlues of microil C-iomss in topsoil under different tillge systems over the time period from 22 to 29. CT conventionl tillge; NT no tillge; MTS minimum tillge + strw; NTM no tillge + mulch. Columns which re designed y the sme letter did not differ significntly (P =.5) PLANT SOIL ENVIRON., 58, 212 (12):

5 stle. C iomss nd C org were decresing in the conventionl tillge tretment, proly due to more intensive minerliztion of the soil orgnic mtter, nd lesser inputs of sustrte nd energy from the crop residues. On the other hnd, there ws n increse in oth C org nd C iomss in no till with mulch tretments (NTM). Apprently, the input of orgnic mtter ws higher nd the minerliztion processes were less intensive in this vrint, compred to the CT tretment. The eneficil effect of crop residues in the no till system, in which crop residues remin on the surfce, nd soil orgnic mtter ccumultes in the upper lyer, ws lso cited y Miknová et l. (29). Lipvský et l. (28), who showed tht the cerel strw nd minerl nitrogen fertilizers my sustitute for frmyrd mnure in its effect on crop yields nd orgnic C content in the topsoil. Our erlier studies (Miknová et l. 29, Šimon et l. 29), s well s some studies y other uthors (Mijngos et l. 26, Mdejón et l. 29, Wng et l. 212) showed tht soil conservtion tillge improves the iologicl properties of soils. REFERENCES Arrúe J.L., Cntero-Mrtínez C., Crdrelli A., Kvvdis V., López M.V., Moreno F., Mret R., Murillo J.M., Pérez de Ciriz J.J., Somrero A., Tenures J.L., Zmrn E. (27): Comprehensive inventory nd ssessment of existing knowledge on sustinle griculture in the Mediterrnen pltform of KASSA. In: Lhmr R., Arrúe J.L., Denrdin J.E., Gupt R.K., Rieiro M.F., de Tourdonnet S. (eds): Knowledge Assessment nd Shring on Sustinle Agriculture. CIRAD, Montpellier, 24 (CD-Rom). Friedrich T. (23): Engineering for conservtion griculturetrends, concepts nd chllenges in glol perspective. In: Proceedings on the Soil Mngement for Sustinility, Brisne Austrli, Jos R., Hereter A. (25): Effects of tillge systems in drylnd frming on ner-surfce wter content during the lte winter period. Soil nd Tillge Reserch, 82: Kldivko J.E. (21): Tillge systems nd soil ecology. Soil nd Tillge Reserch, 61: Lhmr R., de Tourdonnet S., Brz P., Düring R.A., Frielinghus M., Kolli R., Kuát J., Medvedev V., Netlnd J., Picrd D. (26): Prospect for conservtion griculture in northern nd estern Europen countries. Lessons of KASSA. Biliothec Frgment Agronomic, 11: Lhmr R. (21): Adoption of conservtion griculture in Europe. Lessons of the KASSA project. Lnd Use Policy, 27: 4 1. Lipvský J., Kuát J., Zoč J. (28): Long-term effects of strw nd frmyrd mnure on crop yields nd soil properties. Archives of Agronomy nd Soil Science, 54: Mdejón E., Murillo J.M., Moreno F., López M.V., Arrue J.L., Alvro-Fuentes J., Cntero C. (29): Effect of long-term conservtion tillge on soil iochemicl properties in Mediterrnen Spnish res. Soil nd Tillge Reserch, 15: Melero S., Ruiz Porrs J.C., Herenci J.F., Mdejón E. (26): Chemicl nd iochemicl properties in silty lom soil under conventionl nd orgnic mngement. Soil nd Tillge Reserch, 9: Mijngos I., Pérez R., Alizu I., Grisu C. (26): Effects of fertiliztion nd tillge on soil iologicl prmeters. Enzyme nd Microil Technology, 4: Miknová O., Jvůrek M., Šimon T., Friedlová M., Vch M. (29): The effect of tillge systems on some microil chrcteristics. Soil nd Tillge Reserch, 15: Moreno F., Pelegrín F., Fernández J.E., Murillo J.M. (1997): Soil physicl properties, wter depletion nd crop development under trditionl nd conservtion tillge in southern Spin. Soil nd Tillge Reserch, 41: Roger-Estrde J., Anger Ch., Bertrnd M., Richrd G. (21): Tillge nd soil ecology: Prtners for sustinle griculture. Review. Soil nd Tillge Reserch, 111: So H.B., Grski A., Desorough P. (29): The impct of 14 yers of conventionl nd no-till cultivtion on the physicl properties nd crop yields of lom soil t Grfton NSW, Austrli. Soil nd Tillge Reserch, 14: Šimon T., Jvůrek M., Miknová O., Vch M. (29): The influence of tillge systems on soil orgnic mtter nd soil hydrophoicity. Soil nd Tillge Reserch, 15: Šíp V., Růžek P., Chrpová J., Vver R., Kusá H. (29): The effect of tillge prctice, input level nd environment on the grin yield of winter whet in the Czech Repulic. Field Crops Reserch, 113: Vn den Putte A., Govers G., Diels J., Gillijns K., Demuzere M. (21): Assessing the effect of soil tillge on crop growth: A met-regression nlysis on Europen crop yields under conservtion griculture. Europen Journl of Agronomy, 33: Vnce E.D., Brookes P.C., Jenkinson D.S. (1987): An extrction method for mesuring soil microil iomss C. Soil Biology nd Biochemistry, 19: Videnovič Ž., Simič M., Srdič J., Dumnovič Z. (211): Long term effects of different soil tillge systems on mize (Ze mys L.) yields. Plnt, Soil nd Environment, 57: Wng J.J., Li X.Y., Zhu A.N., Zhng X.K., Zhng H.W., Ling W.J. (212): Effects of tillge nd residue mngement on soil microil communities in North Chin. Plnt, Soil nd Environment, 58: Received on July 31, 212 Corresponding uthor: Ing. Olg Miknová, Ph.D., Výzkumný ústv rostlinné výroy, v.v.i., Drnovská 57, Prh-Ruzyně, Česká repulik phone: , e-mil: miknov@vurv.cz 544 PLANT SOIL ENVIRON., 58, 212 (12):